Obesity and esophageal cancer: GERD, Barrett´s esophagus, and molecular carcinogenic pathways

Introduction Increases in the rates of esophageal adenocarcinoma (EAC) have paralleled rises in the prevalence of overweight and obesity. Despite not being fully understood, obesity-related EAC seems to have different carcinogenic pathways.Areas covered This comprehensive review will thoroughly evaluate the current literature, describing the underlying mechanisms that help understanding the strong association between obesity and esophageal cancer.Expert commentary The risk of esophageal cancer among obese individuals could be partially explained by several factors: high prevalence of GERD; linear association between central adiposity and Barrett´s esophagus development; low levels of adiponectin and high levels of leptin that alter cell proliferation processes; insulin-resistant state that creates a tumorigenesis environment; and changes in the esophageal microbiota due to unhealthy dietary habits that promote carcinogenesis. In addition, a large proportion of obese patients are undergoing sleeve gastrectomy which can worsen GERD or cause de novo reflux, esophagitis, and Barrett´s metaplasia.